The present invention relates to an operation unit for electric devices, and more particularly relates to an operation unit adapted for mounting a number of electric operation components such as control switches, control dials and control knobs to a front panel of electric devices such as amplifiers and electric or electronic musical instruments.
In general, an electric device of the above-described type is provided with a great number of electric operation components on the front panel or panels thereof. A typical example of such arrangement is found in the front panel construction of an electronic organ which, as hereinafter described in more detail, in general has four to five sets of front panels each of which includes many electric operation components such as rotary-type volume controllers, slide-type volume controllers, push button switches and so on.
In order to assemble the front panel construction in the conventional manner, it is necessary to fix the electric operation components individually to the associated front panel of the electric device by screw fastening. In addition, there is generally appreciable clearance between a mounting aperture formed in the front panel and an electric operation component to be set to the mounting aperture. Due to presence of such large clearances, it is necessary to readjust the mounting positions of the electric operation components after the above-described mounting so that a number of electric operation components can be beautifully aligned in position on the front panel. Such individual mounting and individual adjustment of the great number of electric operation components naturally lead to enormously increased consumption of time and labor needed for assembly of the front panel construction which is obviously disadvantageous from the view point of productivity and manufacturing cost.
Further, presence of a great number of electric operation components requires use of a great number of electric lead wires for connecting same to associated electric circuit or circuits. Use of such a great number of lead wires again causes increased time and labor needed for connection work and requires enlarged space for accommodating the lead wires which can hardly be obtained on the rear side of the front panel. In addition, complicated arrangement of the great number of lead wires makes it very difficult to carry out possible faculty check after long use of the electric device. Increased number of the lead wires also cause corresponding increase in the installation cost.